I know that you have heard enough about this, but........ I was turning left the other day and when I let off the brake, my 98 Accord with a 2.3 VTEC began to surge strongly. It is better after about 40-45mph. I have burped the coolant system (twice to be sure), changed the pcv (which had no rattle) and checked for vacuum leaks. My scanner shows codes p0420, p1456, p1706 and p1129. Could clean iac, but no code for that. Could clean MAP as there is a code for high value. Some of you may know what I mean when I say - the older you get, the less you enjoy wasting time. Could this all be caused by bad Cat? Sudden onset makes that unlikely, I would think. Those of you with more Honda experience please point me in the right direction. This is my first post on this forum, so excuse my poor etiquette.

 

I always ask this, have you had any recent work done on your car before you had this surge?

Is your car doing this all the time since the first incident?

No sure how often you check the codes, but are any of these codes new? You may want to clear the codes, then see which return to help troubleshoot.

The MAP sensor is catching my attention. You may want to see if it is dirty or the seal is shot on it. I haven't seen to many map sensors fail on here, so you may want to look at the wire harness to the map for any obvious damage or corrosion in the connector. I'd probably get a map sensor from a u-pull-it yard if this were my car, because I'd rather install a used OEM part vs an aftermarket part.